This SCR timer was found in an old English documentation. The SCR can be the TUIC106 and modern equivalent transistors like the BC557 for TR1 and BC547 for the others.
This crystal radio or galena was found in an English documentation from the 70's. The diode must...
We found this circuit in a 2002 documentation. What it does is put in a reduced power outlet for...
This circuit was found in a 1988 publication. The circuit is an alarm with interrupt sensors that...